WSU Extension

Hortsense

Weeds
 
Annual bluegrass 
Barnyardgrass 
Bentgrass, creeping 
Bermudagrass 
Bittercress (Shotweed, Hairy bittercress) 
Bittersweet nightshade (European bittersweet) 
Black medic 
Blackberry (Himalayan, Evergreen, Pacific) 
Blue mustard (Purple mustard, Tenella mustard) 
Brackenfern, western 
Buffalobur 
Bull thistle 
Buttercup, creeping 
Canada thistle 
Catchweed bedstraw (Cleavers) 
Catsear, common (False dandelion) 
Chickweed, common and mouseear 
Clover 
Comfrey 
Crabgrass 
Dandelion 
Dock (Curly, Broadleaf) 
Dodder 
Downy brome (Cheatgrass, Downy chess) 
Dwarf mistletoes 
English daisy (Lawn daisy) 
English ivy 
Field bindweed (Wild morningglory) 
Field pennycress (Fanweed) 
Flixweed 
Foxtail (Green, Yellow, Bristly) 
Garden loosestrife 
Giant hogweed 
Goldenrods 
Groundsel, common 
Hawkweeds 
Hedge bindweed 
Henbit 
Herb Robert (Robert geranium, stinky Bob) 
Horsetails (Scouringrush) 
Horseweed (Marestail) 
Knapweeds 
Knotweeds (Bohemian, Giant, Japanese, Himalayan) 
Kochia 
Lambsquarters, common 
Liverworts 
Mallow, common (Cheeseweed, Buttonweed) 
Nightshades 
Oxalis (Creeping woodsorrel) 
Parrotfeather and Eurasian watermilfoil 
Pineappleweed 
Plantain (Broadleaf, Buckhorn) 
Poison hemlock 
Poison ivy and Poison oak 
Prickly lettuce (China lettuce) 
Prostrate knotweed 
Puncturevine (Tackweed, Goathead) 
Purple deadnettle (Red deadnettle) 
Purple loosestrife (Purple lythrum) 
Purslane, common 
Quackgrass 
Red sorrel (Sheep sorrel) 
Redroot pigweed (Rough pigweed) 
Redstem filaree (Stork's bill, Crane's bill) 
Reed canarygrass 
Russian thistle (Tumbleweed) 
Ryegrass, annual (Italian ryegrass) 
Salsify (Goatsbeard) 
Scotch broom 
Shepherd's-purse 
Smartweeds 
Sowthistle, annual and perennial 
Speedwells 
Spurges (Prostrate spurges) 
St. Johnswort, common (Goatweed, Klamathweed) 
Stinging nettle 
Tansy ragwort 
Tumblemustard (Jim Hill mustard) 
Velvetgrass (Common velvetgrass) 
Velvetleaf 
Water primrose 
Waterhemlock, western 
Yellow nutsedge 



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Caption: Field pennycress fruits
Photo by: D.G. Swan
  
Weeds : Field pennycress (Fanweed) : Thlaspi arvense
(revision date: 6/9/2014)

Family: Brassicaceae (Cruciferae)
Cycle: Annual
Plant Type: Broadleaf

Biology
Field pennycress grows six to eighteen inches tall, branching mainly in the upper, flowering portion of the plant. The leaves are elongate, hairless, and alternate, with larger leaves at the base of the plant and smaller leaves above. The lower leaves have petioles, while the upper leaves lack petioles and may clasp the stem. Leaf shape is variable, with some leaves shallowly toothed and others with smooth margins. Flowers are borne on the tips of branches at the top of the plant. The small blossoms have four white (sometimes pinkish) petals. Flowers occur singly on short stalks. Seeds are borne in a roughly circular pod about 2/5 inch in diameter. The pod has a thickened central portion surrounding the seeds and a thin, fan-like wing surrounding this central part. Mature pods split in half along a center partition. The tiny seeds are dark reddish-brown at maturity. This plant has a strong odor, sometimes described as onion-like.
Habitat
Field pennycress is found in fields, waste places, along roadsides, and in disturbed areas.

Management Options

Non-Chemical Management
  • Reduce weed establishment by maintaining a healthy planting or turf area to provide competition.
  • Cultivation (rototilling or hoeing) will effectively eliminate plants.
  • Hand-pull to eliminate weeds.
  • Mowing to prevent seed production is a very effective means of management. In lawns, mowing regularly at the proper height for the grass species may help minimize weed growth and invasion.
  • Careful digging is useful to manage weed populations. However, digging can carry undesirable weed seed to the surface and foster further germination.
Select non-chemical management options as your first choice!

Chemical Management

Apply according to label directions. Glyphosate and glufosinate products should be applied as spot treatments only! There are also products available to licensed applicators for use to control this weed. NOTE: Some ingredients listed here are only available in combination. Read the label carefully on combination products to make sure the product is suitable for your specific situation.

Landscape areas
  • glyphosate
  • dichlobenil
  • glufosinate
  • products containing diquat
Turf areas
  • products containing 2,4-D
Bare ground areas
  • glyphosate
  • products containing diquat
Images

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Caption: Field pennycress fruits
Photo by: D.G. Swan
Caption: Field pennycress leaves
Photo by: J.A. Kropf
Caption: Field pennycress flower heads
Photo by: R. Parker
Caption: Field pennycress seedling
Photo by: D.G. Swan